Elevated basal and post-feed glucagon-like peptide 1 (GLP-1) concentrations in the neonatal period.
BACKGROUND
Glucagon-like peptide 1 (GLP-1) is an incretin hormone that stimulates glucose-induced insulin secretion, increases beta-cell proliferation, neogenesis and beta-cell mass. In adults, plasma concentrations of amidated GLP-1 are typically within the 5-10 pmol/l range in the fasting state and increases to approximately 50 pmol/l after ingestion of a mixed meal.


METHODS
We measured plasma glucose, insulin and amidated forms of GLP-1 prefeed and then at 20 and 60 min post-feed following ingestion of a 60-70 ml of standard milk feed in preterm (n=10, 34-37 weeks) and term newborn infants (n=12, 37-42 weeks). Reverse-phase fast protein liquid chromatography was used to characterise the molecular nature of the circulating GLP-1.


RESULTS
Mean birth weight was 3.18 kg and mean age at sampling for GLP-1 was 7.7 days. The mean basal GLP-1 concentration was 79.1 pmol/l, which increased to 156.6 pmol/l (+/-70.9, P<0.001) and 121.5 pmol/l (+/-59.2) at 20 and 60 min respectively. Reverse-phase chromatography analysis suggested that the majority of GLP-1 immunoreactivity (>75%) represented GLP-1 (7-36) amide and (9-36) amide.


CONCLUSIONS
Basal and post-feed amidated GLP-1 concentrations in neonates are grossly raised with the major fractions of circulating GLP-1 being (7-36) amide and (9-36) amide. Elevated GLP-1 concentrations in the newborn period may have a role in regulating maturation of enteroendocrine system and also of increasing pancreatic beta-cell mass and regeneration. The high levels of GLP-1 may be due to immaturity of the dipeptidyl peptidase IV and or lower glomerular filtration rate in the neonatal period. Further studies are required to understand the role of GLP-1 in the neonatal period.
Padidela
Raja
R
London Centre for Paediatric Endocrinology and Metabolism, Great Ormond Street, Hospital for Children NHS Trust, London, UK.
Patterson
Michael
M
Sharief
Nawfal
N
Ghatei
Mohammed
M
Hussain
Khalid
K
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000031:analogs & derivatives* / Q000097:blood; D006801:Humans; D007231:Infant, Newborn / Q000097:blood*; D007234:Infant, Premature / Q000097:blood*; D007328:Insulin / Q000097:blood; D008297:Male; D010446:Peptide Fragments / Q000097:blood*; D010455:Peptides / Q000097:blood*; D019518:Postprandial Period; D011446:Prospective Studies; D055815:Young Adult
D001786:Blood Glucose; D007328:Insulin; D010446:Peptide Fragments; D010455:Peptides; C114437:glucagon-like peptide-1 (9-36)-amide; C055453:glucagon-like peptide 1 (7-36)amide; D052216:Glucagon-Like Peptide 1